The present invention pertains to a single facer machine for the manufacture of a single face corrugated web and, more particularly, to a method and apparatus for positioning and locking the glue roll of a separate glue machine with respect to a corrugating roll on the single facer.
In the manufacture of corrugated paperboard, a single facer machine is used to corrugate the medium web, apply glue to the flute tips on one face of the corrugated medium web, and bring a liner web into contact with the glued flute tips of the medium web while applying sufficient heat and pressure to provide an initial bond in the glue lines between the corrugated medium and the liner. For many years, single facers have typically included a pair of fluted corrugating rolls and pressure roll which are aligned so that the axes of all three rolls are generally coplanar. The medium web is fed into a corrugating nip formed by the interengaging corrugating rolls and, while the corrugated medium web is still on one of the corrugating rolls, adhesive is applied to the flute tips by a glue roll. The liner web is immediately thereafter brought into contact with the adhesive-coated flute tips of the medium web and the composite single face web then passes through the nip formed by the corrugating roll and the pressure roll. More recently, a significantly improved single facer machine has been developed in which the corrugating rolls comprise a large diameter heated bonding roll and a substantially smaller diameter corrugating roll, with the ratio of diameters being 3:1 or greater. This more recently developed single facer eliminates the need for a pressure roll.
In both the older style single facer, where the corrugating rolls are of approximately the same diameter, and the more recently developed single facer, where the large diameter fluted bonding roll cooperates with the small diameter fluted corrugating roll, glue that typically comprises a starch adhesive is applied to the flute tips of the corrugated medium web while the web is held on a corrugating roll by the use of a glue application roll. Typically, glue from a reservoir is applied to a doctor roll which in turn transfers a layer of adhesive to the glue roll which is spaced a very small distance from the corrugated medium being carried on one of the corrugating rolls. It is important to carefully control the glue roll gap to assure that a uniform and proper amount of glue is transferred to the flute tips of the medium web.
In modern single facers, it is typical to mount the entire glue machine on a separate and independent frame and to mount the remainder of the single facer apparatus on a main single facer frame. The single facer main frame is set in a fixed position and the glue machine is mounted to move from an operative position with respect to the single facer machine to a spaced position a substantial distance from the single facer. To accommodate this movement, the glue machine is typically mounted on wheels in a manner to permit it to be moved far enough away from the single facer main frame to permit access to both the single facer and the glue machine for maintenance, cleaning and repair. In accordance with the subject invention, an apparatus is disclosed for positioning and locking the glue roll on the glue machine and moving the glue roll into operative running position with respect to a corrugating roll on the single facer machine.
In accordance with the present invention, the glue machine frame is provided with a pair of laterally spaced front wheels that are attached to and support the frame on a rotatable front pivot arm. A pair of laterally spaced rear wheels are attached to and support the glue machine frame on a rotatable rear pivot arm. An actuator device connects the front and rear pivot arms and is operable to initially rotate the front pivot arm to move the front wheels from an idle position supporting the front of the glue machine frame on a horizontal support surface to a locked position with the front wheels lifted from the horizontal surface and the front of the glue machine frame lowered vertically into a pivotal position on laterally spaced support blocks on the glue machine frame. The actuator device is operable thereafter to rotate the rear pivot arm and move the rear wheels over the horizontal surface and to rotate the glue machine frame about the axis of the support blocks from the locked position to a running position defined by a glue machine frame abutment surface in contact with a single facer machine abutment surface.
In accordance with a preferred embodiment, each of the laterally spaced front and rear wheels is attached to the machine frame on a respective rotatable front and rear pivot arm. The actuator device comprises a linear fluid actuator that interconnects a front pivot arm and a rear pivot arm on each lateral side of the glue machine frame. The actuators are operable in unison to move from an extended position that establishes the idle position of the machine to an intermediate position that establishes the locked position, and then to a fully retracted position that establishes the running position. Preferably, each front wheel and each rear wheel is supported, respectively, by a pair of front pivot arms and a pair of rear pivot arms with each pair of arms rotatably supported on a wheel mounting shaft on opposite sides of its respective wheel, and the linear fluid actuators are pairs of air cylinders connecting each front and rear wheel pair. The apparatus also includes a front wheel stop on the glue machine that limits rotation of the front wheel on the front pivot arm in the direction of the locked position and sets said locked position. The apparatus also includes a rear pivot arm stop that is attached to the glue machine frame and limits rotation of the rear pivot arm in the direction of the extended position of the actuator establishing the idle position of the glue machine frame.
In the preferred embodiment, the support blocks comprise a pair of V-blocks, and the glue machine is provided with a pair of laterally spaced rollers that are aligned with the V-blocks in spaced relation thereto in the idle position and which move into bearing contact with the V-blocks in the locked position. In the preferred embodiment, the single facer machine abutment surface comprises a pair of stop blocks attached to the single facer frame, and the glue machine abutment surface comprises a pair of cam followers attached to the glue machine frame. The attachment of each cam follower to the glue machine frame is adjustable to vary the operative position of the glue roll in the running position. The glue machine is movable on the front and rear wheels over the horizontal support surface from the idle position to a service position in which the machine is spaced from the single facer machine.
Further in accordance with the present invention, a method for positioning and locking the glue roll of a glue machine and for moving the glue roll into operative position with respect to the corrugating roll of a single facer machine includes the steps of (1) supporting the glue machine on pairs of laterally spaced front wheels and rear wheels that are attached to the glue machine frame by respective pairs of rotatable front and rear pivot arms, (2) connecting the front and rear pivot arms with a linear actuator, (3) operating the actuator to initially rotate the front pivot arms and to move the front wheels from an idle position supporting the front of the glue machine frame on a horizontal surface to a locked position with the front wheels lifted from the horizontal surface and the front of the glue machine frame lowered vertically onto laterally spaced support blocks on the single facer machine frame, and (4) continuing operating the actuator to rotate the rear pivot arms and to move the rear wheels over the horizontal surface thereby rotating the glue machine on the support blocks from the locked position to a running position with a glue machine frame abutment surface in contact with a single facer machine abutment surface.
In accordance with the preferred method, the linear actuator comprises a fluid cylinder connecting a front pivot arm and a rear pivot arm on each lateral side of the glue machine frame, and the operating steps comprise (1) retracting the cylinders in unison from an extended position establishing the idle position to an intermediate position establishing the locked position, and (2) continuing retracting the cylinders to a retracted position establishing the running position. Most preferably, the fluid cylinders comprise air cylinders, and the method further includes steps of (1) positioning a front pivot arm stop on the glue machine frame in the path of front pivot arm rotation in the retracting direction to prevent rotation thereof past the locked position, and (2) positioning a rear pivot arm stop on the glue machine frame in the path of rear pivot arm rotation in the extending direction to prevent rotation thereof past the idle position.
In the preferred embodiment, the single facer abutment surface comprises a stop block attached to the single facer machine frame and the glue machine abutment surface comprises a cam follower attached to the glue machine frame, and the method comprises the additional step of adjusting the position of the cam follower to vary the operative position of the glue roll in the running position.